Refrigeration



T. SHIPLEY REFRIGERATION July 12, 1932.

Filed 001;. 12. 1927 Patented July 12,1932

and particularly to means for SUSPQIldlIlg' 3 UNITED-"STATES PATENT OFFIQE' moms smLnY, or YomrmrivsYLvANm, ASSIGNOR T0 YORK ICE MACHINES-f! oonronarron, or YORK, PENNSYLVANIA, A CORPORATION or nrmawm REFRIGERATION This invention 'relates to refrigeration,

immediately the refrigerative action of a cooler in which a liquid'refrigerant is used by admitting to the cooler gas under pressure in'such a wayas to displace the refrigerant from the cooler.

In its broad aspects the invention is appli; cable to any cooler using a liquid cooling medium, but-derives peculiar utility as applied to evaporators to-which volatile liquid refrigerant is fed. In' such a case, if reso to operate 1; e device as to establish and maintain'a desired temperature in the evaporator immediately upon the expulsion of the liquid refrigerant. I

The use of high pressure gaseous refrigerant to expel liquid refrigerant from the evaporator and thereafter perform a thawing and defrosting function is not new. In

such prior device the idea. was to condense in the evaporator gaseous refrigerant, the latent heat of vaporization thus madeavailable furnishing the latent heat of fusion necessary for the thawing or defrosting operation. The maintenance of a definite temperature was neither sought nor secured.

The present invention contemplates 1111- mediately establishing and maintaining a definite pressure and consequently adefinite temperature, usually the temperature existing at the moment of unloading so that the transfer of heat to or from tlfe cooler does not occur during the unloading period. Condensation of gaseousrefrigerant in the evaporator istherefore not desired and does not occur in an substantial degree. A partic arly useful application of themventive concept is to the freezing of ice cream, where after a batch has been cooled to the temperature at which the well known swell of the batch commences, the chill; ing function is suspended to permit the swell to occur under the effect of whipping or beating action of the dasher at a maintained optimum temperature. I v

The invention will now be'described as applied to an ice cream freezing plant having Application med matter 12, 1927. Serial No. 225,775.

flooded evaporators, but, as stated, this specific disclosure is intended to be merely illustrative of the preferred embodiment of the invention. In the drawing,'- v

Fig. 1 is a diagrammatic view, largely in vertical section, showing the connections for three freezers. Fig. 2 is a section showing the valves in unloaded position. v

' Fig. 3 is a similar view showing thevalves in freezing position. frig'erant gasunder a definite pressure be used as the dis lacing medium, it is possible.

In the. drawing,'6 is a combined low pressure receiver and suction trap, fed from a 9 leads from the top of receiver 6 to the suction of the compressor (not shown). The arrangement so far described is familiar in the art.

Three ice cream freezers are indicated, 11 being the space in which the ice cream is frozen, and the jacket 12 being a flooded evaporator servingto abstract heat from the space 11. A feed pipe13 leads from the bottom of receiver 6 and has branches 14, one

'lea'dingto the jacket 12 of each freezer. In

each branch 14 is interposed a check valve 15 which opens toward the evaporator-12 and which is normally held open by a float 16.

The float 8 functions to stop flow to receiver 6 at such a level that evaporators 12 are substantially filled. At such times valves 15 are I open ready to permit back flow from the corresponding evaporator. 12 through branch 14 to pipe 13. When any evaporator has been drained the float 16 of the corresponding valve 15 falls and valve 15' closes tightly against further back flow.-

Leading from the tops of the eva rators 12 are corresponding suction branc es 17 all connected to suction line 18 which enters receiver 6 from the top. The receiver 6 thus serves as a separator or trap for arresting liquid refrigerant and preventing it from enterin suction line 9. Each branch 17 is controll ed by a valve 19 shown as a cock, but permissibly of any preferred construction.

A hot gas bleeder 21 leads from the high pressure gas line between the compressor and condenser (not shown) and has branches 22,

each connected toa'corresponding evaporator 12 preferably by bein connected with branch 17 below valve 19. 11 each branch 22 there is a sto' valve 23 (shown as a cock) and an adjusta ly loaded back pressure valve 24 of any preferred construction. Such a valve is ordinarily urged o em byentering pressure,

to which is oppose a spring and some means for adjusting the stress in the spring. The handwheel- 25 represents such'an ad]ustable stressing means. Such a valve is indicated merely as t 'pical of any simple adjustablea chamber 11.

the hot pressure-re ucing valve, and ;no novelty is claimed for the structure of the valve per se.v

Gages 26 are connected to show the press'ures in corresponding evaporators. The actuating handles 27 and 28 of valves 1 19 and 23 are connected by an actuating-bar 29 in such manner that the valves are opened in alternation with each other in the two opposite positions (see Figs. 2 and 3).

'After the chamber; 11 is charged with a batch to be frozen the member 29 is moved to the position of Fig. 3 if not already there. This opens the suction connection after clos-. ing the hot connection andevaporator 12 then fills with liquid refrigerant which vaporizes, abstracting heat from the cream in (See middle and right hand freezers of Fig. 1).

When the swell commences, member 29' is moved to the'right to the position of Fig. 2,

closing the suction connection and opening as connection. Wheel 25 is then so adjusts "(unless already so adjusted) as to limit the rise oflpressure in evaporator 12, with a consequent establishment of achosen temperature in the evaporator. With the parts in this condition, the cream in chamber 11 is beaten by the dasher (not-shown) Various changes may obviously be made in the construction and arrangement of the parts, and no necessary limitation to the construction shown is implied.

For example, while the feature of establishinga chosen temperature, durin' the unloaded operation is dependent on t e use ofan evaporative cooler, the useful eflfect dependcut on the expulsion of the liquid medium from the evaporator may be. secured 'with coolers using other liquidcooling media.

Certain claims of the present application are drawn to this broad idea and are not limited to evaporative coolers.

What is claimed is 1. The method of'unloadinga cooler having-an inlet connection and an outlet connection for the circulation of a refrigerating medium through the cooler, which consists in arresting the circulation and admitting gas under pressure to expel the liquid medium from the cooler.

2. The method of unloadinga cooler having an inlet connection and an outlet connection for the circulation of a refrigerating medium,

which'consists in closing one of said connections, admitting gas under pressure to said I cooler to expel said medium through the other o said connections and automatically clos ing said other connection upon the substan-- tial depletion suction connection, admitting hot gas to displace liquid through the liquid connection, controlling the admission-of such hot gas to establish within the evaporator a pressure corresponding to the desired temperature in the evaporator during the'unloading period, and terminating the outflow of liquid refrigerant in response to the substantial depletion of liquid refrigerant in the evaporator.

I -5-. The combination of a cooler having a supply connection for heat absorbingliquid, a discharge connection and a connection for gas under pressure; a valve adapted to close against outflow through said supply connece tion; automatic means responsive to liquid level arranged to hold said valve open when liquid is present in said cooler; and valve means controlling said discharge and pressure gas connections. v a

6. The combination of a flooded evaporator having a liquidsrefrigerant supply connection, a suction connection and a high pressure gas connection; a valve adapted to close against outflow through'said supply connection; automatic means responsive to liquid level arranged to hold said valve open when liquid is present in said evaporator; and valve means controlling said suction and high pressure gas connections.

7. The combination of a flooded evaporator having a liquid refrigerant supply connec- 1 ,tion, a suction connection'and'a high pressure gas connection; a valve adapted to close against outflowthrough said supply connec tion; va floatarranged to hold sald valve open when liquid is present in said evaporator;

valve means controlling said suction and high pressure gas connections; and manually operable means for opening either of the lastnamed connections, while maintaining the other closed;

8. The combination of a flooded evaporator having a suction connection and a high presre gas connection; meansoperable to .openeither connection while maintaining the other closed; valve-controlled means for discharg-, ing liquid refrigerantfrom the evaporator when displaced by high pressure gas; and means responsiveto the depletion. of liquid serving to close the last-named valve against outflow of gas.

. 9. The combination of a flooded evaporator having a suction connection and a high'pres-- sure-gas connection; means operable to open either connection while maintaining the other "closed; valve-controlled means for discharging liquid refrigerant from the evaporator when displaced by high pressure gas; and a float responsive to the presence of liquid within the evaporator and connected to said valve-controlled means to open the latter-for the passage of liquid and close it against the passage of gas.

10. The combination of a flooded evaporator having a high pressure gas connection for expelling liquid refrigerant from the evaporator; and a pressure responsive valve controlling the flow of gas through said connection and serving to limit the pressure thereby established in the evaporator.

to permit the discharge of liquid refrigerant from the evaporator when subjected to the pressure of high pressure gas, and to prevent the passage of high pressure gas through the liquidrefrigerant supply connection.

In testimony whereof I have signed my name to this specification.

- THOMAS SHIPLEY.

11. The combination of a flooded evap- I orator having a high pressure gas connection for' expelling liquid refrigerant from the evaporator; a pressure responsive valve controlling theflow of gas through said con nection and serving to limit the pressure manually operable meansfor adjusting said valve to vary its pressure limiting function.

12. The combination of a flooded evaporator having a high pressure gas connection for expelling liquid refrigerant from the evap.

'thereby established in the evaporator; and

orator; a pressure responsiye valve controlling the flow of gas through said connection and serving to limit the pressure thereby established in the evaporator; and valve means in the path ofthe outflow of liquid from the evaporator responsive to the depletion of liquid arranged to close against the outflow of gas.

13. The combination of a flooded evaporator having a high pressure gas connection for expelling liquid-refrigerant from the evaporator; a pressure responsive valve controlling the flow of gas through said connection and serving to limit the pressure the'rebyestablished in the evaporator; manually -operable means for adjusting said valve to vary its pressure limiting function; and valve means in the path of the outflow of liquid from the evaporator responsive to depletion of liquid and arranged to close against the outflow of gas.

14. The combination of a flooded evaporator having a suction connection, a high pressure gas connection and a liquid refrigerant supply connection; means operable to open either the suction connection or the high ressure gas connection whilemaintaming t e other closed; and means serving 

